On Mon, Aug 22, 2011 at 06:52:33PM +0300, Amit Kucheria wrote:
"Nacked-by: Peter Zijlstra a.p.zijlstra@chello.nl
the kernel really shouldn't be using hotplug for this (nor should userspace really). hot-unplugging random cpus wrecks things like cpusets. Furthermore hotplug does way too much work to use as a simple means to idle a cpu.
Even the availability of this mask is wrong, since that implies the information is useful, which per the above it is not, the kernel shouldn't care about this full-stop.
The only reason for the OS to unplug a CPU is imminent and unavoidable hardware failure. Thermal capping is not that (and yes ACPI-4.0 is a broken piece of shit)."
Thanks! This is a good opener for the TSC session I suggested. :-)